"The fact that one species may evolve more than another within the same family, or in a different way, does not change anything about that family of species because ducks are still ducks."
By the exact definitions of species that you base your belief system on, Mallard and Blacks (interbreeding) are 'micro-evolving' whereas Mallards and Teal (non-interbreeding) are not 'macro-evolving'.
So you see, the common definition of species that you seem to put so much value on is pretty silly when applied to something as simple as 'if it looks like a duck, quacks like a duck, then it is a duck'.
